1. Field of the Invention
The present invention relates to an alloy tool of hard metal employed for machining work, and more particularly, it relates to a cutter etc. such as a cutting tool, drill or a die made of cemented carbide.
2. Description of the Prior Art
Cemented carbide is generally employed to make cutting tools including drill bits. Such cemented carbide is superior in hardness, abrasion resistance etc. to high speed steel, whereas the same is inferior in toughness. Therefore, improvements in the strength of cemented carbide are desirable.
In hard metal represented by such cemented carbide, the tensile strength is generally smaller than the compressive strength. Therefore, the strength of a tool itself corresponds to its tensile strength. Thus, the tool itself cannot attain considerable strength since its tensile strength is inferior although the tool has a high compressive strength.